Gas turbine engines (sometimes called aero gas turbines) may include a number of ducts (sometimes called pipes) which carry high pressure air from a compressor to the turbine. The ducts may carry the high pressure air externally to the engine casings. The air may be used to cool the turbine components and/or to control the movement of oil within bearings. Alternatively, ducts may be used to supply air for other purposes such as a cabin air system and bleed valves.
Ducts may contain flow controllers to switch them from high flow to no-flow or a low flow condition. The gas supply system comprising the ducts may be designed to provide enough flow at high power/low altitude conditions (e.g. during take off). This flow is enough to over supply the turbine during cruise conditions. By reducing the flow in cruise conditions, fuel can be saved.
If there is a fault in the gas supply system comprising the ducts, then this can result in a great deal of damage. For example, the nacelle and/or components within the turbine zone may be overheated.
One approach is to detect faults through visual inspection by maintenance personnel. However, it can take many flights to detect faults in this way.
Accordingly, it is desirable to make it easier and quicker to detect faults in the gas supply system for the gas turbine engine.